"Next season we'll actually jump forward about six months, so we're deep into the war," he told TV Guide. "He's now killed Batiatus (John Hannah) and Glaber (Craig Parker)... the question is, 'What drives him now?'

"But the question does rise, 'How do you define victory? When is it enough?' This will be a question that will haunt Spartacus throughout the season... 'When is war over? Is it ever over?'

"Historically people have a very romanticised vision of Spartacus and his rebels... It does get dirty and it does get very grey next season. Everyone morally and ethically gets a little muddied."

DeKnight did warn fans not to expect Lucretia (Lucy Lawless) to have a major influence in season three, confirming that the character had been killed off in the Vengeance finale.

"I never rule out a good flashback," he said. "The concern was that in the second season, should we bring back what is arguably the biggest name in the show? I was adamant, 'No she has to die. It wouldn't work any other way'."